No, he did not kill her. She committed suicide after seeing that Romeo was dead.
Romeo killed himself after finding what he believed to be Juliet's dead body.
Mercutio was killed when Tybalt stabbed him in the begging of Romeo and Juliet.
Romeo didn't kill Juliet. Juliet outlived him.
In Romeo and Juliet, Tybalt kills Romeo's friend Mercutio, so Romeo kills Tybalt. Romeo kills Paris and then himself, thinking that Juliet is dead. Juliet wakes up from her sleep and, seeing Romeo dead, kills herself. At the end we find out that Romeo's mother dies because of grief over the banishment of her son.
They killed themselves
he is nothing after juliet, he killed himself.
Juliet killed herself and Romeo drank poison because he thought Juliet was already dead.
Mercutio
Juliet doubts Romeo momentarily when she finds out that he has killed Tybalt in 3,2. Romeo never doubts Juliet.
Because Romeo thought that Juliet was dead since she took a potion that made her look dead. Romeo therefore killed himself. When Juliet woke up and saw that Romeo was dead she also killed herself. Romeo killed himself with poison and Julet killed herself with a dagger.
When Romeo killed Tybalt after Tybalt killed Mercutio
Romeo.